#header{
    width: 100%;
    background-color: orange;
    display: flex;
    .mui-icon{
        font-size: 0.3rem;
        align-self:center;
    }
    h4{
        font-size: 0.3rem;
        align-self:center;
    }
    .fa-download{
        font-size: 0.3rem;
        align-self:center;
        position: absolute;
        right:0;
    }
}

。dongxi{
    
}